Heat exchanger for cooled cooling air with adjustable damper

ABSTRACT

A heat exchanger (HEX) for cooling air in a gas turbine engine is provided. An adjustable damper is provided. The adjustable damper may be for damping a movement of the HEX relative to the gas turbing engine. An adjustable damper may comprise: a first tube; a second tube located at least partially within the first tube; a housing coupled to the second tube; a moveable member, the moveable member comprising a contacting surface in contact with the second tube; an adjusting member adjustably coupled to the housing; and a spring member located between the moveable member and the adjusting member, the spring member configured to at least one of compress or decompress in response to adjusting member moving relative to the housing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part application of and claimspriority to U.S. patent application, application Ser. No. 14/826,905,filed on Aug. 14, 2015 and entitled “FOLDED HEAT EXCHANGER FOR COOLEDCOOLING AIR” which is hereby incorporated by reference in its entiretyfor all purposes. This application is a nonprovisional application ofand claims priority to U.S. Provisional Patent Application, ApplicationNo. 62,278,649, filed on Jan. 14, 2016 and entitled “FOLDED HEATEXCHANGER FOR COOLED COOLING AIR” which is hereby incorporated byreference in its entirety for all purposes.

FIELD

The present disclosure relates to gas turbine engines, and, morespecifically, to heat exchangers (HEX) for cooling air of gas turbineengines.

BACKGROUND

As higher pressures are achieved in compressors of gas turbine engines,the temperature of compressed air in and/or leaving the compressors mayincrease as well. As a result, various components in a gas turbineengine may experience thermal stress. Thus, a heat exchanger (HEX) maybe provided to cool hot air in a gas turbine engine. The heat exchangermay experience various loads and modes of vibration relative to the gasturbine engine.

SUMMARY

A heat exchanger for cooling air in a gas turbine engine may comprise: acentral manifold comprising an inlet portion, a first outlet portion,and a second outlet portion; a plurality of tubes coupled to the centralmanifold; a shroud at least partially encasing said plurality of tubes;and a cooling air flow path defined by at least one of the shroud, theplurality of tubes, and an outer surface of the central manifold,wherein the cooling air flow path is orthogonal to said plurality oftubes, the heat exchanger being coupled to the gas turbine engine via aplurality of links; and an adjustable damper coupled between the heatexchanger and the gas turbine engine, the adjustable damper comprising:a first tube, a second tube configured to be inserted at least partiallyinto the first tube, and an adjusting member.

In various embodiments, the adjustable damper may further comprise amoveable member and a spring member coupled between the adjusting memberand the moveable member. The adjustable damper may further comprise ahousing coupled to the first tube, the spring member and the adjustingmember located at least partially within the housing. The moveablemember may comprise a contacting surface configured to contact thesecond tube. The contacting may dampen a movement of the second tubealong a longitudinal axis. The adjusting member may be threadinglyattached to the housing, the spring member configured to compress inresponse to the adjusting member being turned into the housing anddecompress in response to the adjusting member being turned out of thehousing. The first outlet portion may be located on the opposite side ofthe inlet portion as the second outlet portion. The cooling air flowpath may receive air from a bypass flow path of the gas turbine engine.The inlet portion may be configured to receive air from a high pressurecompressor section of the gas turbine engine.

A gas turbine engine may comprise: a compressor section; and anair-to-air heat exchanger in fluid communication with the compressorsection, comprising: a central manifold comprising an inlet portion, afirst outlet portion, and a second outlet portion; a plurality of tubesconfigured to receive air from the compressor section coupled to thecentral manifold; a shroud at least partially encasing said plurality oftubes; and a cooling air flow path defined by at least one of theshroud, the plurality of tubes, and an outer surface of the centralmanifold, wherein the cooling air flow path is orthogonal to saidplurality of tubes, wherein, the air-to-air heat exchanger is coupled tothe gas turbine engine via an adjustable damper comprising: a firsttube; a second tube located at least partially within the first tube; anadjusting member; a moveable member; and a spring member located betweenthe adjusting member and the moveable member.

In various embodiments, the moveable member may comprise a contactingsurface, the moveable member being in contact with the second tube viathe contacting surface. The adjusting member may be adjustably coupledto a housing. A force may be transferred from the first tube, throughthe housing, through the adjusting member, through the spring member,into the moveable member, and into the second tube. The force may beconfigured to dampen a movement of the second tube along a longitudinalaxis. The spring member may be configured to at least one of compress ordecompress in response to the adjusting member moving relative to thehousing. The housing may be attached to the first tube, the moveablemember in contact with the second tube via a cut-out in the first tube.The first outlet portion may be located on the opposite side of theinlet portion as the second outlet portion. The inlet portion mayreceive air from the compressor section of the gas turbine engine andthe cooling air flow path receives air from a bypass flow path of thegas turbine engine.

An adjustable damper may comprise: a first tube; a second tube locatedat least partially within the first tube; a housing coupled to thesecond tube; a moveable member, the moveable member comprising acontacting surface in contact with the second tube; an adjusting memberadjustably coupled to the housing; and a spring member located betweenthe moveable member and the adjusting member, the spring memberconfigured to at least one of compress or decompress in response to theadjusting member moving relative to the housing.

In various embodiments, a force may be transferred from the first tube,through the housing, through the adjusting member, through the springmember, into the moveable member, and into the second tube via thecontacting surface for damping a movement of the second tube in alongitudinal direction.

The forgoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated hereinotherwise. These features and elements as well as the operation of thedisclosed embodiments will become more apparent in light of thefollowing description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the detailed description and claims whenconsidered in connection with the figures, wherein like numerals denotelike elements.

FIG. 1 illustrates a cross-sectional view of an exemplary gas turbineengine, in accordance with various embodiments;

FIG. 2 illustrates a cross-sectional view of an exemplary gas turbineengine, in accordance with various embodiments;

FIG. 3 illustrates the primary-flow gas path in a gas turbine enginethrough the low pressure compressor, high-pressure compressor,combustor, high-pressure turbine, and low-pressure turbine, inaccordance with various embodiments;

FIG. 4 illustrates a cross-sectional view of a heat exchanger, inaccordance with various embodiments;

FIG. 5 illustrates a cross-sectional view of a heat exchanger, inaccordance with various embodiments;

FIG. 6 illustrates a cross-sectional view of a central manifold, inaccordance with various embodiments;

FIG. 7A illustrates a cross-sectional view of part of a central manifoldwith tubes installed in a stepped manner, in accordance with variousembodiments;

FIG. 7B illustrates a cross-sectional view of part of a central manifoldwith tubes installed with a smooth change in radial position, inaccordance with various embodiments;

FIG. 8 illustrates a cross-sectional view of a cooling air flow paththrough heat exchanger tubes installed in an alternating manner, inaccordance with various embodiments;

FIG. 9 illustrates a perspective view of a heat exchanger installed on agas turbine engine, in accordance with various embodiments;

FIG. 10A illustrates a cross-section view of a heat exchanger, inaccordance with various embodiments;

FIG. 10B illustrates a perspective view of a baffle for a heatexchanger, in accordance with various embodiments;

FIG. 10C illustrates a baffle with an oxidized layer, in accordance withvarious embodiments;

FIG. 11 illustrates an adjustable damper, in accordance with variousembodiments;

FIG. 11A illustrates an adjustable damper with a reference washer, inaccordance with various embodiments; and

FIG. 12 illustrates a heat exchanger and a gas turbine engine with anadjustable damper coupled between the heat exchanger and the gas turbineengine, in accordance with various embodiments.

DETAILED DESCRIPTION

The detailed description of exemplary embodiments herein makes referenceto the accompanying drawings, which show exemplary embodiments by way ofillustration. While these exemplary embodiments are described insufficient detail to enable those skilled in the art to practice theinventions, it should be understood that other embodiments may berealized and that logical changes and adaptations in design andconstruction may be made in accordance with this invention and theteachings herein. Thus, the detailed description herein is presented forpurposes of illustration only and not of limitation. The scope of theinvention is defined by the appended claims. For example, the stepsrecited in any of the method or process descriptions may be executed inany order and are not necessarily limited to the order presented.Furthermore, any reference to singular includes plural embodiments, andany reference to more than one component or step may include a singularembodiment or step. Also, any reference to attached, fixed, connected orthe like may include permanent, removable, temporary, partial, fulland/or any other possible attachment option. Additionally, any referenceto without contact (or similar phrases) may also include reduced contactor minimal contact. Surface shading lines may be used throughout thefigures to denote different parts but not necessarily to denote the sameor different materials. In some cases, reference coordinates may bespecific to each figure.

As used herein, “aft” refers to the direction associated with the tail(e.g., the back end) of an aircraft, or generally, to the direction ofexhaust of the gas turbine. As used herein, “forward” refers to thedirection associated with the nose (e.g., the front end) of an aircraft,or generally, to the direction of flight or motion. As used herein,“gas” and “air” may be used interchangeably.

Fuel efficiency of gas turbine engines is known to be proportional tothe ratio of the exit pressure and the inlet pressure of the engine, oroverall pressure ratio (OPR). As the OPR increases, the efficiency ofthe engine generally increases. However, a byproduct of OPR is highoperating temperatures in various portions of the engine, such as thehigh pressure compressor for example. Materials used in gas turbineengines have temperature thresholds which cannot be surpassed forsuccessful operation. Cooling air may be used to decrease operatingtemperatures of various components in a gas turbine engine. Generally,air from a compressor section of a gas turbine engine is used to coolother sections of the engine. However, as the OPR of gas turbine enginesincreases, the air from the compressor section may become increasinglyhot. A heat exchanger (HEX) may be used to cool the air from acompressor section, thus providing cooled cooling air.

FIG. 1 illustrates a schematic view of a gas turbine engine, inaccordance with various embodiments. Gas turbine engine 110 may includecore engine 120. Core air flow C flows through core engine 120 and isexpelled through exhaust outlet 118 surrounding tail cone 122.

Core engine 120 drives a fan 114 arranged in a bypass flow path B. Airin bypass flow-path B flows in the aft direction (z-direction) alongbypass flow-path B. At least a portion of bypass flow path B may bedefined by nacelle 112 and inner fixed structure (IFS) 126. Fan case 132may surround fan 114. Fan case 132 may be housed within fan nacelle 112.

With momentary reference to FIG. 2, nacelle 112 typically comprises twohalves which are typically mounted to pylon 270. Fan case structure 233may provide structure for securing gas turbine engine 110 to a pylon160. According to various embodiments, multiple guide vanes 116 mayextend radially between core engine 120 and IMC 134.

Upper bifurcation 144 and lower bifurcation 142 may extend radiallybetween the nacelle 112 and IFS 126 in locations opposite one another toaccommodate engine components such as wires and fluids, for example.

Inner fixed structure 126 surrounds core engine 120 and provides corecompartments 128. Various components may be provided in core compartment128 such as fluid conduits and/or a compressed air duct 130, forexample. Compressed air duct 130 may be under high pressure and maysupply compressed cooling air from a compressor stage to a high pressureturbine stage, for example. In various embodiments, a heat exchanger maybe coupled to compressed air duct 130.

With respect to FIG. 2, elements with like element numbering as depictedin FIG. 1 are intended to be the same and will not necessarily berepeated for the sake of clarity.

In various embodiments and with reference to FIG. 2, a gas turbineengine 110 is provided. Gas turbine engine 110 may be a two-spoolturbofan that generally incorporates a fan section 222, a compressorsection 224, a combustor section 226 and a turbine section 228.Alternative engines may include, for example, an augmentor section amongother systems or features. In operation, fan section 222 can drive airalong a bypass flow-path B while compressor section 224 can drive airalong a core flow-path C for compression and communication intocombustor section 226 then expansion through turbine section 228.Although depicted as a turbofan gas turbine engine 110 herein, it shouldbe understood that the concepts described herein are not limited to usewith turbofans as the teachings may be applied to other types of turbineengines including three-spool architectures.

Gas turbine engine 110 may generally comprise a low speed spool 230 anda high speed spool 232 mounted for rotation about an engine centrallongitudinal axis A-A′ relative to an engine static structure 236 viaone or more bearing systems 238 (shown as bearing system 238-1 andbearing system 238-2 in FIG. 2). It should be understood that variousbearing systems 238 at various locations may alternatively oradditionally be provided including, for example, bearing system 238,bearing system 238-1, and bearing system 238-2.

Low speed spool 230 may generally comprise an inner shaft 240 thatinterconnects a fan 114, a low pressure (or first) compressor section244 and a low pressure (or first) turbine section 246. Inner shaft 240may be connected to fan 114 through a geared architecture 248 that candrive fan 114 at a lower speed than low speed spool 230. Gearedarchitecture 248 may comprise a gear assembly 260 enclosed within a gearhousing 262. Gear assembly 260 couples inner shaft 240 to a rotating fanstructure. High speed spool 232 may comprise an outer shaft 250 thatinterconnects a high-pressure compressor (“HPC”) 252 (e.g., a secondcompressor section) and high pressure (or second) turbine section 254. Acombustor 256 may be located between HPC 252 and high pressure turbine254. A mid-turbine frame 257 of engine static structure 236 may belocated generally between high pressure turbine 254 and low pressureturbine 246. Mid-turbine frame 257 may support one or more bearingsystems 238 in turbine section 228. Inner shaft 240 and outer shaft 250may be concentric and rotate via bearing systems 238 about the enginecentral longitudinal axis A-A′, which is collinear with theirlongitudinal axes. As used herein, a “high pressure” compressor orturbine experiences a higher pressure than a corresponding “lowpressure” compressor or turbine.

The core airflow C may be compressed by low pressure compressor 244 thenHPC 252, mixed and burned with fuel in combustor 256, then expanded overhigh pressure turbine 254 and low pressure turbine 246. Mid-turbineframe 257 includes airfoils 259 which are in the core airflow path. Lowpressure turbine 246 and high pressure turbine 254 rotationally drivethe respective low speed spool 230 and high speed spool 232 in responseto the expansion.

Gas turbine engine 110 may be, for example, a high-bypass gearedaircraft engine. In various embodiments, the bypass ratio of gas turbineengine 110 may be greater than about six (6). In various embodiments,the bypass ratio of gas turbine engine 110 may be greater than ten (10).In various embodiments, geared architecture 248 may be an epicyclic geartrain, such as a star gear system (sun gear in meshing engagement with aplurality of star gears supported by a carrier and in meshing engagementwith a ring gear) or other gear system. Geared architecture 248 may havea gear reduction ratio of greater than about 2.3 and low pressureturbine 246 may have a pressure ratio that is greater than about 5. Invarious embodiments, the bypass ratio of gas turbine engine 110 isgreater than about ten (10:1). In various embodiments, the diameter offan 114 may be significantly larger than that of the low pressurecompressor 244, and the low pressure turbine 246 may have a pressureratio that is greater than about 5:1. Low pressure turbine 246 pressureratio may be measured prior to inlet of low pressure turbine 246 asrelated to the pressure at the outlet of low pressure turbine 246 priorto an exhaust nozzle. It should be understood, however, that the aboveparameters are exemplary of various embodiments of a suitable gearedarchitecture engine and that the present disclosure contemplates othergas turbine engines including direct drive turbofans. FIG. 1 and FIG. 2provide a general understanding of the sections in a gas turbine engine,and is not intended to limit the disclosure. The present disclosure mayextend to all types of turbine engines, including turbofan gas turbineengines and turbojet engines, for all types of applications.

With respect to FIG. 3, elements with like element numbering as depictedin FIG. 1 and FIG. 2 are intended to be the same and will notnecessarily be repeated for the sake of clarity.

FIG. 3 illustrates the primary flow gas path through core engine 110, inaccordance with various embodiments. Core engine 110 may include enginestatic structure 236, low-pressure compressor 244, high-pressurecompressor 252, combustor 256, high-pressure turbine 254, andlow-pressure turbine C. Engine static structure 236 may be referred toas an engine case. Gas may flow into low-pressure compressor 244 alonggas path C. Gas flowing through low-pressure compressor 244 along gaspath C may be compressed, resulting in an increase in pressure andtemperature relative to the pressure and temperature upon enteringlow-pressure compressor 244. Gas may flow into high-pressure compressor252 along gas path C. Gas flowing through high-pressure compressor 252along gas path C may be compressed, resulting in an increase in pressureand temperature relative to the pressure and temperature upon enteringhigh-pressure compressor 252. Uncombusted gas in gas path C leavinghigh-pressure compressor 252 may be referred to as T3 gas. T3 gas mayhave a varying temperature at different engine speeds. The temperatureof T3 gas may be about 400° F. (205° C.) when core engine 110 is at idlespeeds and may reach about 1,400° F. (760° C.) or higher as core engine110 accelerates for takeoff, where the term “about” in this context onlymay refer to +/−200° F. (+/−93.3° C.). Different engines may have highertemperatures or lower temperatures at each stage. T3 gas may be presentat location 314 of core engine 110. T3 gas leaving the high-pressurecompressor 252 may then flow into combustor 256 to supply combustor 256with air for combustion.

In various embodiments, uncombusted T3 gas may be mixed with fuel andburned in combustor 256. Combusted gas in combustor 256 may be referredto as T4 gas. T4 gas may leave combustor 256 and enter high-pressureturbine 254. T4 gas may reach or exceed temperatures of up to 3,500° F.(1,925° C.) or higher. T4 gas may be located at location 316, forexample. T4 gas leaving combustor may follow gas path C to drivehigh-pressure turbine 254.

In various embodiments, combusted gas that has entered, but not exited,high-pressure turbine 254 may be identified as T4.25 gas. T4.25 gas maybe significantly cooler than T4 gas exiting combustor 256. For example,T4.25 gas may be at temperatures of about 1,000° F.-2,000° F. (537°C.-1,093° C.), where the term “about” in this context only may refer to+/−500° F. (+/−260° C.). T4.25 gas may be located at location 318, forexample. The T4.25 gas then follows out high-pressure turbine 254 andinto low-pressure turbine 246 along gas path C.

In various embodiments, combusted gas exiting high-pressure turbine 254and entering low-pressure turbine 246 may be referred to as T4.5 gas.T4.5 gas may be cooler than T4.25 gas found in the high-pressurecompressor or T4 gas exiting the combustor. For example, T4.5 gas may beabout 1,500° F. (815° C.) degrees at idle, where the term “about” inthis context only may refer to +/−500° F. (+/−260° C.). T4.5 gas may belocated at location 320 in gas path C, for example. The T4.5 gas thenfollows gas path C into low-pressure turbine 246.

With reference to FIG. 4, a cross-section view of a heat exchanger (HEX)400 is illustrated. An x-y-z axis is provided for ease of illustration.In various embodiments, HEX 400 may comprise a central manifold 410 anda plurality of tubes 430. In various embodiments, central manifold 410may comprise an inlet portion 412, a first outlet portion 414, and asecond outlet portion 416. In various embodiments, first outlet portion414 may be located on the opposite side of inlet portion 412 as secondoutlet portion 416. In various embodiments, first outlet portion 414 maybe located adjacent to inlet portion 412 (in the positive y-direction).In various embodiments, second outlet portion 416 may be locatedadjacent to inlet portion 412 (in the negative y-direction). In variousembodiments, inlet portion 412, first outlet portion 414, and secondoutlet portion 416 may each individually define a cylindrical void. Invarious embodiments, HEX 400 may further comprise a shroud 450. Invarious embodiments, shroud 450 may be coupled to central manifold 410.Shroud 450 may at least partially encase central manifold 410 and tubes430.

In various embodiments, a plurality of baffles, such as baffle 436 forexample, may be coupled to plurality of tubes 430. Baffle 436 maycomprise a plurality of apertures into which plurality of tubes 430 areinserted. Baffle 436 may add to the stiffness of plurality of tubes 430.In various embodiments, with momentary reference to FIG. 1, the numberof baffles installed over plurality of tubes 430 may be determined bythe highest operating frequency of gas turbine engine 110. For example,baffles, such as baffle 436 may be installed over plurality of tubes 430until the natural frequency of plurality of tubes 430 is higher than thehighest operating frequency of gas turbine engine 110. In variousembodiments, a baffle support 438 may be coupled to baffle 436.

With reference now to FIG. 3 and FIG. 4, in various embodiments, centralmanifold 410 and/or plurality of tubes 430 may be made of a highperformance nickel-chromium alloy such as an austeniticnickel-chromium-based superalloy (e.g., INCONEL or HAYNES 282), metals,ceramics, or other materials suitable to withstand T3 gas temperaturesthat may exceed 1,100° F. (593° C.) degrees when core engine 120 isoperating at takeoff speeds.

With respect to FIG. 5, FIG. 6, FIG. 7A, FIG. 7B, and FIG. 8, elementswith like element numbering as depicted in FIG. 4 are intended to be thesame and will not necessarily be repeated for the sake of clarity.

With reference now to FIG. 5, inlet portion 412 may comprise fourquadrants including quadrant 502 (also referred to herein as “firstquadrant”), quadrant 504 (also referred to herein as “second quadrant”),quadrant 506 (also referred to herein as “third quadrant”), and quadrant508 (also referred to herein as “fourth quadrant”). First outlet portion414 may comprise first half 512 and second half 514. Second outletportion 416 may comprise first half 522 and second half 524. In variousembodiments, a plurality of tubes, including tube 432, may be coupledbetween quadrant 504 of inlet portion 412 and second half 514 of firstoutlet portion 414. In various embodiments, a plurality of tubes,including tube 434, may be coupled between quadrant 508 of inlet portion412 and second half 524 of second outlet portion 416. In variousembodiments, a plurality of tubes, including tube 536, may be coupledbetween quadrant 502 of inlet portion 412 and first half 512 of firstoutlet portion 414. In various embodiments, a plurality of tubes,including tube 538, may be coupled between quadrant 506 of inlet portion412 and first half 522 of second outlet portion 416. Accordingly, inletportion 412 may be in fluid communication with first outlet portion 414and in fluid communication with second outlet portion 416. In variousembodiments, central manifold 410 may comprise a hexagonal geometry asillustrated in FIG. 5. In various embodiments, central manifold 410 maycomprise an octagonal, square, ovular, elliptical, and/or any othergeometry.

In various embodiments, as illustrated in FIG. 5, tube 536 may comprisea straight portion 596 and a rounded portion 598. Accordingly, tube 536may be folded, in half for example. Thus, HEX may be referred to ashaving a folded tube design.

In various embodiments, plurality of tubes 430 may comprise an upperstack (also referred to herein as “first stack”) 590 and a lower stack(also referred to herein as a “second stack”) 592. In variousembodiments, with momentary reference to FIG. 4 and FIG. 8, bafflesupport 438 may be configured to block air in cooling air flow path Ffrom entering the void 563 located in the middle of upper stack 590 ofplurality of tubes 430. In various embodiments, baffle support 438 mayprovide support for a plurality of baffles such as baffle 436. Invarious embodiments, baffle support 438 may comprise a plurality ofapertures, such as aperture 439, through which at least a portion of aplurality of baffles, such as a portion of baffle 436, may be insertedand coupled to baffle support 438. In various embodiments, bafflesupport 438 may be welded, soldered, brazed, or otherwise suitablycoupled to baffle 436. One or more baffle supports may be located withinthe void in the middle of lower stack 592 in a similar manner as bafflesupport 438.

With reference now to FIG. 4, inlet portion 412 may include a firstattachment feature 442 and a second attachment feature 444. In variousembodiments, first attachment feature 442 may define a hemisphericalvoid. In various embodiments, second attachment feature 444 may define ahemispherical void. In various embodiments, first attachment feature 442may be detachably coupled to inlet portion 412. In various embodiments,first attachment feature 442 may be permanently coupled to inlet portion412. For example, first attachment feature 442 may be welded, soldered,brazed, or otherwise suitably coupled to inlet portion 412. In variousembodiments, second attachment feature 444 may be detachably coupled toinlet portion 412. In various embodiments, second attachment feature 444may be permanently coupled to inlet portion 412. For example, secondattachment feature 444 may be welded, soldered, brazed, or otherwisesuitably coupled to inlet portion 412.

In various embodiments, air may enter HEX 400 via inlet tube 404. Invarious embodiments, HEX 400 may be coupled via inlet tube 404 to a highpressure compressor such as high-pressure compressor 252 of FIG. 2 andFIG. 3. Accordingly, HEX 400 may be in fluid communication via inletportion 412 with a compressor section 224 of a gas turbine engine. Invarious embodiments, HEX 400 may be coupled via inlet tube 404 to acompressor section, combustor section, and/or a turbine section of a gasturbine engine. In various embodiments, HEX 400 may be coupled to anyportion of a gas turbine engine.

In various embodiments, HEX 400 may comprise hot air flow path E. Hotair flow path E may be defined by inlet portion 412, plurality of tubes430, first outlet portion 414, and/or second outlet portion 416. Uponentering inlet portion 412 via inlet tube 404, air may follow hot airflow path E and enter the plurality of tubes 430 from inlet portion 412and then exit the plurality of tubes 430 into one of first outletportion 414 and/or second outlet portion 416. For example, air may enterinlet portion 412, then enter tube 432, next it may exit tube 432 intofirst outlet portion 414, and finally exit first outlet portion 414 viafirst outlet tube 406. In a further example, air may enter inlet portion412, then enter tube 434, next it may exit tube 434 into second outletportion 416, and finally exit second outlet portion 416 via secondoutlet tube 408. Air exiting either first outlet portion 414 or secondoutlet portion 416 may be used to cool various portions of a gas turbineengine. In various embodiments, while in plurality of tubes 430, air inhot air flow path E may transfer heat to air in cooling air flow path F.

In various embodiments, inner surface 454 of shroud 450 may at leastpartially define a cooling air flow path F. Outer surface 418 of centralmanifold 410 may at least partially define cooling air flow path F. Theouter surface of the plurality of tubes 430 may at least partiallydefine cooling air flow path F. In various embodiments, air from bypassflow path 124 of FIG. 1 may enter cooling air flow path F. In variousembodiments, air in cooling air flow path F may flow generally in an aftdirection (positive z-direction). In various embodiments, heat from airin the plurality of tubes 430 may be transferred to air in cooling airflow path F. In various embodiments, the transfer of heat may occur in aconvective manner. Accordingly, the temperature of air in inlet portion412 may be greater than the temperature of air in first outlet portion414 and second outlet portion 416. In various embodiments, the flow ofair in plurality of tubes 430 may be orthogonal to the flow of air incooling air flow path F. Thus, the flow of air in tubes 430 and the flowof air in cooling air flow path F may comprise a cross-flow.Accordingly, plurality of tubes 430 may extend in a direction which isorthogonal to cooling air flow path F.

In various embodiments, a pressure gradient may exist between air in hotair flow path E and cooling air flow path F. In various embodiments, aspreviously mentioned, inlet portion 412, first outlet portion 414, andsecond outlet portion 416 may each individually define a cylindricalvoid as shown in FIG. 4 and FIG. 5. In various embodiments, air pressurein inlet portion 412 may reach up to 500 pounds per square inch absolute(500 psia) (3,447,378.6 Pascal) or more, while air pressure in coolingair flow path F may generally vary between 14.7 psia (101,352.9 Pascal)and 21 psia (144,789.9 Pascal). In various embodiments, the cylindricalgeometry of inlet portion 412, first outlet portion 414, and secondoutlet portion 416 may be ideal to handle the amount of pressureexperienced by these portions. In various embodiments, air entering hotair flow path E may reach temperatures of about 1,400° F. (760° C.) orhigher. In various embodiments, with reference to FIG. 3, air enteringhot air flow path E may comprise T3 gas. In various embodiments, airentering cooling air flow path F may reach temperatures of about 100° F.(38° C.) or higher. In various embodiments, air entering cooling airflow path F may comprise engine bypass air. In various embodiments,engine bypass air may comprise air from bypass flow path 124 of FIG. 1.

With reference to FIG. 8, cross-section view of plurality of tubes 430installed in an alternating manner with a detailed view of cooling airflow path F is illustrated, according to various embodiments. An x-y-zaxis is provided for ease of illustration. In various embodiments,plurality of tubes 430 may be installed in an alternating manner. Forexample, column 804 of plurality of tubes 430 may be offset (in they-direction) from column 802 such that column 804 is not directly behind(in the z-direction) column 802. Installing tubes 430 in an alternatingmanner may aide in more efficiently transferring heat from air inplurality of tubes 430 to air in flow path F.

In various embodiments, shroud 450 may include flow tab 452. In variousembodiments, flow tab 452 may comprise a tab or panel. In variousembodiments, flow tab 452 may be configured to contain cooling air flowpath F in close proximity to plurality of tubes 430 which may aide inmore efficiently transferring heat from air in plurality of tubes 430 toair in flow path F.

With reference to FIG. 6, a cross-section view of a central manifold 410is illustrated. An x-y-z axis is provided for ease of illustration. Invarious embodiments, central manifold 410 may comprise one or morerelief cuts 670. Relief cut 670 may be located between inlet portion 412and first outlet portion 414. Relief cut 670 may be located betweeninlet portion 412 and second outlet portion 416. Relief cut 670 may beconfigured to relieve stress from central manifold 410 as centralmanifold 410 expands and contracts in response to an increase anddecrease in temperature respectively. In various embodiments, centralmanifold 410 may comprise a plurality of apertures 660 such as aperture662 for example. With momentary reference to FIG. 4, plurality ofapertures 660 may be configured to receive plurality of tubes 430.Plurality of tubes 430 may be inserted from an outer surface 666 ofcentral manifold 410 to an inner surface 668 of central manifold 410 inthe x-direction. In various embodiments, plurality of tubes 430 may bedetachably coupled to central manifold 410. In various embodiments,plurality of tubes 430 may be permanently coupled to central manifold410. For example, tube 432 may be welded, soldered, brazed, or otherwisesuitably coupled to central manifold 410 via aperture 662. In variousembodiments, plurality of tubes 430 may be flush with inner surface 668when in an installed position. In various embodiments, plurality oftubes 430 may protrude radially inward from inner surface 668 when in aninstalled position.

With reference to FIG. 7A, plurality of tubes 430 are illustrated in aninstalled position in a stepped fashion, according to variousembodiments. Plurality of tubes 430 may comprise various sections oftubes, each installed at different radial positions. For example,plurality of tubes 430 may comprise various sections of tubes such assection 702, section 704, and section 706. In various embodiments,section 702 may protrude further radially inward than section 704. Invarious embodiments, section 704 may protrude further radially inwardthan section 706. In various embodiments, with momentary reference toFIG. 7B, plurality of tubes 430 may comprise a gradual or smooth changein radial position as illustrated in FIG. 7B, as opposed to a steppedchange as illustrated in FIG. 7A. In various embodiments, inlet portion412 may comprise a pressure gradient along the axial direction(z-direction). Installing plurality of tubes 430 in a stepped fashionmay compensate for such pressure gradient resulting in a more uniformflow through plurality of tubes 430. In various embodiments, pluralityof tubes 430 may be pre-cut to size before installing into centralmanifold 410. In various embodiments, plurality of tubes 430 may beinstalled into central manifold 410 and then cut to length when in theinstalled position. For example, each tube of plurality of tubes 430 maycomprise a similar length, installed into central manifold 410, and thencut to various lengths according to pre-determined specifications. Invarious embodiments, one or more orifices may be coupled to an inlet ofplurality of tubes 430 in order to meter the flow of air throughplurality of tubes 430.

In various embodiments, each tube included in plurality of tubes 430 maycomprise a physical flow area which is less than 5% of the flow area ofinlet portion 412. With further reference to FIG. 4, inlet portion 412may comprise inner diameter 478, where the flow area of inlet portion412 is calculated as ntimes one fourth times inner diameter 478 squared,or (π/4)*(inner diameter 478)². Similarly, the inner diameter of eachtube included in plurality of tubes 430 may comprise a flow area. Forexample, according to various embodiments, tube 432 may comprise a flowarea which is less than 5% of the flow area of inlet portion 412. Invarious embodiments, tube 432 may comprise a flow area in the range fromabout 1% to about 7% of the flow area of inlet portion 412, wherein theterm “about” in this context can only mean+/−1%. Minimizing the flowarea of tube 432 may allow room for more tubes to be included inplurality of tubes 430, thus increasing the overall surface area ofplurality of tubes 430. Increasing the overall surface area of pluralityof tubes 430 may increase the rate at which heat may be transferred fromair in plurality of tubes 430 to air in cooling air flow path F.Similarly, the flow area of first outlet portion 414 and the flow areaof second outlet portion 416 may be less than the flow area of inletportion 412.

In various embodiments, HEX 400 may be configured such that the flowarea of inlet portion 412 is equal to the flow area of first outletportion 414 and the flow area of second outlet portion 416. In variousembodiments, two outlets may enable the length of plurality of tubes 430to be decreased while maintaining similar heat transfer between hot airflow path E and cooling air flow path F, in comparison with a singleoutlet design. A pressure drop (or difference) may exist between inletportion 412 and both first outlet portion 414 and second outlet portion416. In various embodiments, splitting the flow of hot air flow path Ein half between first outlet portion 414 and second outlet portion 416may decrease the pressure drop between the inlet and outlet by half, incomparison with a single outlet design. Stated another way, having twooutlets, with hot air flow path E split between the two outlets viaplurality of tubes 430, may decrease the pressure drop between inletportion 412 and outlet portions 414, 416 by half. It may be desirable todecrease the pressure drop between the inlet and outlet of HEX 400 inorder to prevent reverse flow or stagnated flow through HEX 400.

With respect to FIG. 9 a heat exchanger (HEX) installed on a gas turbineengine is illustrated, in accordance with various embodiments. Invarious embodiments, HEX 900 may be similar to HEX 400 as illustrated inFIG. 4. In various embodiments, HEX 900 may comprise an inlet portion912, first outlet portion 914, second outlet portion 916, and aplurality of tubes (not shown in FIG. 9). HEX 900 may further compriseshroud 950. Inlet tube 904 may be coupled to inlet portion 912 of HEX900. First outlet tube 906 may be coupled to first outlet portion 914 ofHEX 900. Second outlet tube 908 may be coupled to second outlet portion916 of HEX 900.

In various embodiments, HEX 900 may be coupled to core engine 120 viafirst attachment feature 942 and second attachment feature 944. Invarious embodiments, first attachment feature 942 may be similar tofirst attachment feature 442 as illustrated in FIG. 4. In variousembodiments, second attachment feature 944 may be similar to secondattachment feature 444 as illustrated in FIG. 4. In various embodiments,first attachment feature 942 may be coupled to core engine 120 via oneor more links, such as first link 920 for example. In variousembodiments, first link 920 may be a turnbuckle link. FIG. 9 illustratesfirst attachment feature 942 comprising a plurality of tabs, such as tab943 for example. A bolt or fastener may be inserted through one or moreapertures in link 920 and one or more apertures in tab 943 to couplelink 920 and first attachment feature 942. First link 920 may extendgenerally in the z-direction. Second link 922 and third link 924 may becoupled to first attachment feature in a similar manner as first link920. Second link 922 may extend away from first attachment feature 942generally in the negative x-direction. Third link 924 may extend awayfrom first attachment feature 942 generally in the positive x-direction.Accordingly, first attachment feature may be fixed in space. Statedanother way, first attachment feature may be fixed in the x, y, andz-directions.

In various embodiments, second attachment feature 944 may be coupled tocore engine 120. Second attachment feature 944 may be coupled to coreengine 120 via fourth link 926. In various embodiments, secondattachment feature 944 may be coupled to core engine 120 such thatsecond attachment feature 944 may be free to move in the z-direction.Accordingly, second attachment feature 944 may be configured to freelyexpand away from or contract towards first attachment feature 942 withHEX 900 in response to an increase or decrease in temperature,respectively. In various embodiments, with momentary reference to FIG.2, centerline 998 of HEX 900 may be oriented at an angle in the rangefrom about zero degrees (0°) to about five degrees (5°), wherein theterm “about” in this context can only mean+/−3°. In various embodiments,centerline 998 of HEX 900 may be oriented at an angle of about fivedegrees) (5°), wherein the term “about” in this context can onlymean+/−2°.

With reference to FIG. 11, an adjustable damper 180 is illustrated, inaccordance with various embodiments. With momentary reference to FIG. 9,although heat exchanger (HEX) 900 is illustrated as being connected tocore engine 120 via first link 920, second link 922, third link, 924,and fourth link 926, HEX 900 may be coupled to core engine 120 viaadjustable damper 180 in a manner similar to first link 920, second 922,third link, 924, and fourth link 926. For example, first tube 190 ofadjustable damper 180 may comprise a first terminus 196. Second tube 192of adjustable damper 180 may comprise a second terminus 198. Withmomentary additional reference to FIG. 9, first terminus 196 may beconfigured to be attached to core engine 120, in accordance with variousembodiments. First terminus 196 may be configured to be attached to HEX900, in accordance with various embodiments. Second terminus 198 may beconfigured to be attached to core engine 120, in accordance with variousembodiments. Second terminus 198 may be configured to be attached to HEX900, in accordance with various embodiments. Thus, in variousembodiments, adjustable damper 180 may be for connecting HEX 900 to coreengine 120.

In various embodiments, adjustable damper 180 may comprise an adjustingmember 182, a housing 184, a spring member 186, a moveable member 188, afirst tube 190, and a second tube 192. In various embodiments, adjustingmember 182 may be adjustably coupled to housing 184. Stated another way,adjusting member 182 may be coupled to housing 184 such that adjustingmember may be adjusted to move adjusting member 182 with respect tohousing 184. In various embodiments, adjusting member 182 may bethreadingly attached to housing 184 as illustrated in FIG. 11. Invarious embodiments, adjusting member 182 may comprise a bolt or thelike. In various embodiments, spring member 186 may be coupled betweenmoveable member 188 and adjusting member 182. Moveable member 188 may belocated at least partially within housing 184. Moveable member 188 maybe moveably retained, at least in part, by housing 184. Second tube 192may be configured to be inserted into first tube 190. First tube 190 andsecond tube 192 may comprise a longitudinal axis 194. Thus, second tube192 may move along longitudinal axis 194 relative to first tube 190.

In various embodiments, housing 184 may be coupled to a cut-out 191located on first tube 190. Housing 184 may be coupled to cut-out 191 viaa weld, solder, braze, or any other suitable method. In variousembodiments, housing 184 may be coupled to first tube 190 proximatecut-out 191. In various embodiments, moveable member 188 may comprise acontacting surface 189. Moveable member 188 may be configured to contactsecond tube 192 via contacting surface 189. Contacting surface 189 maydampen the movement of second tube 192 via a friction force. Moveablemember 188 may be in contact with second tube 192 via cut-out 191.Stated another way, moveable member 188 may extend through cut-out 191.A force may be transferred from first tube 190, through housing 184,through adjusting member 182, through spring member 186, into moveablemember 188, and into second tube 192. The magnitude of this force may beadjusted by turning adjusting member 182 into and/or out of housing 184.For example, the magnitude of the force may increase in response toturning adjusting member 182 into housing 184 and may decreases inresponse to turning adjusting member 182 out of housing 184. Statedanother way, the spring member 186 may compress in response to adjustingmember 182 being turned into housing 184 and spring member 186 maydecompress in response to adjusting member 182 being turned out ofhousing 184. Adjusting member 182 may be turned in a rotationaldirection, as illustrated by arrow 183, relative to housing 184.

As illustrated in FIG. 11, spring member 186 may comprise a coil spring.However, spring member 186 may comprise a Belleville washer, a leafspring, or any other suitable spring, in accordance with variousembodiments. Spring member 186 may compress in response to adjustingmember 182 being turned into housing 184. Spring 186 may extend inresponse to adjusting member 182 being turned out of housing 184.

With reference to FIG. 11A, adjustable damper 180 is illustrated havinga washer (also referred to herein as a reference washer) 185. Washer 185may comprise a thickness 187. It may be desirable to provide a referencefor how many turns an operator should turn adjusting member 182 intohousing 184. Thus, washer 185 may be placed between adjusting member 182and housing 184. In this fashion, washer 185 may perimetrically surroundadjusting member 182. Adjusting member 185 may be turned, or otherwisemoved, into housing 184 until adjusting member 182 contacts washer 185,at which point washer 185 may prevent adjusting member 182 from beingturned into housing 184. Accordingly, the thickness 187 of washer 185may determine the position of adjusting member 182 relative to housing184. Over time, contacting surface 189 may wear due to vibration ormotion of first tube 192 relative to contacting surface 189.Furthermore, the spring constant of spring member 186 may change overtime due to various loads such as mechanical and thermal loading. Thus,washer 185 may be exchanged for a second washer comprising a decreasedthickness. In this manner, adjusting member 182 may be turned furtherinto housing 184 with the washer having a decreased thickness incomparison with washer 185 having thickness 187.

In various embodiments, with further reference to FIG. 12, althoughadjustable damper 180 may be used to connect HEX 900 to core engine 120,adjustable damper 180 may be used to dampen a movement of HEX 900relative to core engine 120. For example, a movement of HEX 900 relativeto core engine 120 may be identified in the radial or y-direction, asillustrated in FIG. 12. Thus, adjustable damper 180 may be coupledbetween HEX 900 and core engine 120 to dampen the movement. In responseto the movement, first tube 190 may move relative to second tube 192 andin response contacting surface 189 may dampen said movement.

In various embodiments, with reference to FIG. 10A, a cross-section viewof a heat exchanger 10 is illustrated. With momentary reference to FIG.4, heat exchanger 10 may be similar to HEX 400. In various embodiments,heat exchanger 10 may comprise an inlet 12, an outlet 14, one or moretubes, such as plurality of tubes 20, and a baffle 16. In variousembodiments, plurality of tubes 20 may include tube 22, for example.Tube 22 may comprise a first end 24 and a second end 26. First end 24may be coupled to inlet 12. Second end 26 may be coupled to outlet 14.In various embodiments, air for cooling (or hot air) may enter inlet 12,travel through hot air flow path 40 into plurality of tubes 20, and exitplurality of tubes 20 into outlet 14. In various embodiments, withmomentary reference to FIG. 4, baffle 16 may be similar to baffle 436.

With reference to FIG. 10A and FIG. 10B, a perspective view of baffle 16is illustrated in FIG. 10B, in accordance with various embodiments.Plurality of tubes 20 may be inserted into one or more apertures, suchas aperture 28 for example, in baffle 16. In various embodiments, baffle16 may be fixed to an adjacent component such as a heat exchanger shroudor other fixed object. Cooling air flow path 42 may comprise air whichflows across plurality of tubes 20. In various embodiments, heat may betransferred from air in hot air flow path 40 to air in cooling air flowpath 42. Thus, air entering heat exchanger 10 may comprise a greatertemperature than air exiting heat exchanger 10. In various embodiments,plurality of tubes 20 may extend in the x-direction. In variousembodiments, cooling air flow path 42 may flow generally in thez-direction. Thus, cooling air flow path 42 and hot air flow path 40 mayform a cross-flow. However, cooling air flow path 42 and hot air flowpath 40 may comprise a cross-flow, counter-flow, co-flow, or any othertype of flow. Stated another way, the orientation of hot air flow path40 relative to cooling air flow path 42 may be in any direction.

In various embodiments, with reference to FIG. 10 C, baffle 16 may bemade of a cobalt alloy (e.g., HAYNES 188) or other materials suitable tocreate an oxidized layer when exposed to temperatures that may exceed1,000° F. (538° C.) degrees. In various embodiments, baffle 16 may beconfigured to form an oxidized layer 30 over an outer surface, such asaperture 28, of the baffle in response to an increase in temperature. Invarious embodiments, with further reference to FIG. 10A, the oxidizedlayer 30 may provide a lubricating surface over which plurality of tubes20 may easily slide across. For example, tube 22 may expand or contractin an axial direction (x-direction in FIG. 10A) in response to anincrease or decrease, respectively, in temperature. Thus, tube 22 mayeasily slide through aperture 28 across oxidized layer 30. Oxidizedlayer 30 may prevent or lessen stress in heat exchanger 10 duringexpansion and/or contraction.

Benefits, other advantages, and solutions to problems have beendescribed herein with regard to specific embodiments. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical system. However, the benefits,advantages, solutions to problems, and any elements that may cause anybenefit, advantage, or solution to occur or become more pronounced arenot to be construed as critical, required, or essential features orelements of the inventions. The scope of the inventions is accordinglyto be limited by nothing other than the appended claims, in whichreference to an element in the singular is not intended to mean “one andonly one” unless explicitly so stated, but rather “one or more.”Moreover, where a phrase similar to “at least one of A, B, or C” is usedin the claims, it is intended that the phrase be interpreted to meanthat A alone may be present in an embodiment, B alone may be present inan embodiment, C alone may be present in an embodiment, or that anycombination of the elements A, B and C may be present in a singleembodiment; for example, A and B, A and C, B and C, or A and B and C.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “various embodiments”, “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described. After reading the description, itwill be apparent to one skilled in the relevant art(s) how to implementthe disclosure in alternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element herein is to be construed under theprovisions of 35 U.S.C. 112(f), unless the element is expressly recitedusing the phrase “means for.” As used herein, the terms “comprises”,“comprising”, or any other variation thereof, are intended to cover anon-exclusive inclusion, such that a process, method, article, orapparatus that comprises a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus.

What is claimed is:
 1. A heat exchanger for cooling air in a gas turbineengine comprising: a central manifold comprising an inlet portion, afirst outlet portion, and a second outlet portion; a plurality of tubescoupled to the central manifold; a shroud at least partially encasingsaid plurality of tubes; and a cooling air flow path defined by at leastone of the shroud, the plurality of tubes, and an outer surface of thecentral manifold, wherein the cooling air flow path is orthogonal tosaid plurality of tubes, the heat exchanger being coupled to the gasturbine engine via a plurality of links; and an adjustable dampercoupled between the heat exchanger and the gas turbine engine, theadjustable damper comprising: a first tube, a second tube configured tobe inserted at least partially into the first tube, an adjusting member;a moveable member disposed perpendicular to the second tube, themoveable member comprising a contacting surface configured to contact anouter surface of the second tube and dampen movement of the second tubeby friction force; a spring member coupled between the adjusting memberand the moveable member; a housing coupled to the first tube, whereinthe spring member and the adjusting member are located at leastpartially within the housing; and an adjustable washer sandwichedbetween the housing and the adjusting member having a selected thicknesswhich limits a distance the adjusting member is moved towards thehousing and configured to determine the positioning of the adjustingmember relative to the housing, wherein the adjustable washer is one ofa plurality of adjustable washers of a varying predetermined thickness,the varying predetermined thickness being determined as a function basedon a value of a changing of a spring constant of the spring member overtime.
 2. The heat exchanger of claim 1, wherein the adjusting member isthreadingly attached to the housing, the spring member configured tocompress in response to the adjusting member being turned into thehousing and decompress in response to the adjusting member being turnedout of the housing.
 3. The heat exchanger of claim 1, wherein the firstoutlet portion is located on the opposite side of the inlet portion asthe second outlet portion.
 4. The heat exchanger of claim 1, wherein thecooling air flow path receives air from a bypass flow path of the gasturbine engine.
 5. The heat exchanger of claim 1, wherein the inletportion is configured to receive air from a high pressure compressorsection of the gas turbine engine.
 6. A gas turbine engine comprising: acompressor section; and an air-to-air heat exchanger in fluidcommunication with the compressor section, comprising: a centralmanifold comprising an inlet portion, a first outlet portion, and asecond outlet portion; a plurality of tubes configured to receive airfrom the compressor section coupled to the central manifold; a shroud atleast partially encasing said plurality of tubes; and a cooling air flowpath defined by at least one of the shroud, the plurality of tubes, andan outer surface of the central manifold, wherein the cooling air flowpath is orthogonal to said plurality of tubes, wherein, the air-to-airheat exchanger is coupled to the gas turbine engine via an adjustabledamper comprising: a first tube; a second tube located at leastpartially within the first tube; an adjusting member; a moveable memberdisposed perpendicular to the second tube, the moveable membercomprising a contacting surface configured to contact an outer surfaceof the second tube and dampen movement of the second tube by frictionforce; and a spring member coupled between the adjusting member and themoveable member a housing coupled to the first tube, wherein the springmember and the adjusting member are located at least partially withinthe housing; and an adjustable washer sandwiched between the housing andthe adjusting member having a selected thickness which limits a distancethe adjusting member is moved towards the housing and configured todetermine the positioning of the adjusting member relative to thehousing, wherein the adjustable washer is one of a plurality ofadjustable washers of a varying predetermined thickness, the varyingpredetermined thickness being determined as a function based on a valueof a changing of a spring constant of the spring member over time. 7.The gas turbine engine of claim 6, wherein a force is transferred fromthe first tube, through the housing, through the adjusting member,through the spring member, into the moveable member, and into the secondtube.
 8. The gas turbine engine of claim 7, wherein the housing isattached to the first tube, the moveable member in contact with thesecond tube via a cut-out in the first tube.
 9. The gas turbine engineof claim 7, wherein the force is configured to dampen a movement of thesecond tube along a longitudinal axis.
 10. The gas turbine engine ofclaim 9, wherein the spring member is configured to at least one ofcompress or decompress in response to the adjusting member movingrelative to the housing.
 11. The gas turbine engine of claim 6, whereinthe first outlet portion is located on the opposite side of the inletportion as the second outlet portion.
 12. The gas turbine engine ofclaim 6, wherein the inlet portion receives air from the compressorsection of the gas turbine engine and the cooling air flow path receivesair from a bypass flow path of the gas turbine engine.